Best Reverse Osmosis Water Filters UK 2026
Reverse osmosis is the gold standard in water filtration — removing up to 99.99% of contaminants including PFAS, lead, chlorine, fluoride, microplastics and dissolved solids. We’ve reviewed the best RO systems available in the UK, all from Waterdrop — the leading NSF-certified brand with tankless designs that fit under any kitchen sink.
Top picks at a glance
| Type | Product | Best For | Price Range |
|---|---|---|---|
| Tankless RO | Waterdrop G3P600 | Best overall RO | ~£400 |
| High-capacity RO | Waterdrop X16 | Premium/large families | ~£1,499 |
| Budget under-sink | Waterdrop TSA 3-Stage | Entry-level filtration | ~£119 |
The picks
Waterdrop G3P600 Reverse Osmosis System
Best Overall RO- •Price: ~£399.99 (was £549.98)
- •Tankless design — no bulky storage tank
- •8-stage filtration, removes up to 99.99% of contaminants incl. PFAS, lead, arsenic, fluoride
- •Capacity: 600 GPD (gallons per day)
- •Meets EU and UK household water safety standards
- •Dedicated faucet included
The G3P600 is the RO system we recommend to most people. The tankless design means no bulky storage tank under your sink — you get a constant supply of fresh filtered water without the stagnation risk of traditional RO tanks. It removes virtually everything: PFAS, lead, arsenic, chlorine, fluoride, microplastics, even dissolved solids. The 600 GPD capacity is more than enough for a family of four. Installation is straightforward on UK plumbing with the included adaptors.
Get the Waterdrop G3P600 RO System →Waterdrop X16 Reverse Osmosis System
Best Premium RO- •Price: ~£1,499
- •16-stage reverse osmosis — comprehensive contaminant removal
- •Tankless, dedicated faucet included
- •Capacity: 1600 GPD — handles large households
- •Highest flow rate in the Waterdrop range
The X16 is Waterdrop’s flagship. If you want the absolute best water quality possible in a UK home, this is it. Same contaminant removal as the G3P600 but with higher capacity, faster flow rate, and additional filtration stages. Ideal for large families, hard water areas, or anyone who wants comprehensive removal of microplastics, PFAS, pharmaceuticals and dissolved solids.
Explore the Waterdrop X16 RO System →Waterdrop TSA 3-Stage Under Sink Filter
Best Budget Option- •Price: ~£118.99 (was £139.99)
- •8-stage deep filtration — reduces chlorine, fluoride, heavy metals, sediment
- •Direct connect to existing faucet, no separate tap needed
- •NSF/ANSI 42 certified
- •No wastewater (unlike RO)
Not ready to commit to a full RO system? The TSA is the entry point we’d recommend. It connects directly to your existing kitchen faucet — no drilling, no separate tap — and uses 8-stage deep filtration. It doesn’t remove dissolved solids like RO does, but it handles chlorine, fluoride, heavy metals and sediment without wasting water. At ~£119, it’s the most affordable certified under-sink option in the UK.
Get the Waterdrop TSA from Waterdrop UK →Buying guide — how to choose
What is Reverse Osmosis?
Reverse osmosis forces water through a semi-permeable membrane at molecular level — removing contaminants that carbon filters can’t touch. RO removes: PFAS (forever chemicals), lead, arsenic, chlorine, fluoride, microplastics, pharmaceuticals, dissolved solids, and bacteria.
RO vs Carbon Filters
Carbon filters (like Brita jugs) remove chlorine, taste and odour — that’s it. RO removes those plus dissolved solids, heavy metals, PFAS and microplastics. If you’re concerned about what’s actually in your water beyond taste, RO is the answer.
Tankless vs Tank RO
Traditional RO systems store filtered water in a tank — which can stagnate. Tankless systems (like the G3P600 and X16) produce filtered water on demand, so every glass is fresh.
Does RO waste water?
Yes — traditional RO systems produce 3-4 gallons of wastewater per gallon of filtered water. The Waterdrop G3P600 improves this ratio significantly with a 1.5:1 pure-to-drain ratio — far more efficient than older systems.
Installation
All Waterdrop RO systems are designed for DIY installation on UK plumbing (15mm/1/2" pipes). No plumber required for most kitchens.